A. Field of the Invention
The present invention relates in general to entertainment broadcast systems that transmit and receive a wide variety of video, audio, software and other types of data. More particularly, it relates to a multi-channel broadcast system that transmits a video/text/graphic-based program guide data stream that is used at viewer stations to generate a user interface that facilitates a user's selection of various programs and services.
B. Description of Related Art
The use of electronic communications media to provide access to large amounts of video, audio, textual and data information is becoming more frequent. For example, the public switched telephone network (PSTN) is routinely used to transmit low speed digital data to and from personal computers. Cable television infrastructure is used to carry, via coaxial cable, analog or digital cable television signals, and may also be used to provide high speed Internet connections. In general, cable television infrastructures include many head end or transmission stations that receive programming from a variety of sources, then distribute the programming to local subscribers via a coaxial cable network. Large Direct-to-Home (DTH) satellite communications systems transmit directly to viewers over one hundred fifty audio and video channels, along with very high speed data. DTH systems typically include a transmission station that transmits audio, video and data to subscriber stations, via satellite.
One particularly advantageous DTH satellite system is the digital satellite television distribution system utilized by the DIRECTV® broadcast service. This system transports digital data, digital video and digital audio to a viewer's home via high-powered Ku-band satellites. The various program providers send programming material to transmission stations. If the programming is received in analog form, it is converted to digital. The transmission stations compress the digital video/audio programming (if needed), encrypt the video and/or audio, and format the information into data “packets” that are multiplexed with other data (e.g., electronic program guide data) into a plurality of bitstreams, which include identifying headers. Each packetized bitstream is modulated on a carrier and transmitted to a satellite, where it is relayed back to earth and received and decoded by the viewer's receiver station. The receiver station includes a satellite antenna and an integrated receiver/decoder (IRD). The IRD may be connected to appropriate output devices, typically including a video display.
In general, DTH satellite(s) broadcast on several frequencies from multiple transponders at differing polarizations (e.g., left and right hand circular polarization), and each transponder bitstream includes the video and audio data packets (in a compressed format) for several different programs (or “viewer channels”). For example, transponder ONE may broadcast the digital video and audio data packets for ESPN, TNT, AMC, A&E, E!, STARZ and USA, in a statistically multiplexed fashion. Satellites or other distribution systems which require separate input processing (e.g., satellites at two separated locations requiring different antennas) may also be used. Accordingly, in order to receive a desired viewer channel, the receiver station must know the transponder frequency and the polarization at which the desired signal information is being broadcast by the satellite, along with the identifying header information for those data packets on that transponder that relate to the desired program to permit its isolation from the multiplexed bitstream.
Each satellite transponder broadcasts a program guide data stream, which typically includes not only broadcast schedule data, but also the aforementioned information that the receiver station needs in order to tune to a particular channel. The program guide data stream is broadcast on all satellite transponders so that channel selection information is always available to the IRD regardless of the channel to which the IRD is tuned.
The data packets are distinguished from one another by their header information, which is referred to as the packet's “service channel ID” (SCID). For example, if a viewer instructs the IRD to display ESPN, the IRD, via the tuning information in the program guide data stream, determines the transponder frequency and polarization at which the ESPN programming is broadcast, along with the SCIDs of the data packets that are needed to generate and display the video, audio, and data content of the ESPN program.
The scheduling data in the program guide data packets also provide channel and program-attribute information that is used by the IRD to construct and output as a viewable display (which may be a full or a partial screen) a text-based listing of programming channels, times, titles, descriptions, ratings, etc. In operation, a program guide display is typically presented as a grid having channels listed along the left, times across the top, and program titles shown within the grid squares. Users can scroll through the grid, either up and down (by channel) or to the left and right (by time). Channels can be selected by inputting the channel number directly using the number keys on a user's remote control, or channels may be selected from the program guide display by highlighting and selecting a currently broadcast program that is listed in the grid. In either case, the IRD tunes to the chosen channel by accessing the channel's transponder (frequency), polarization, and SCID information denoted by the program guide data stream.
An extension of known IRD equipment is a PC-based system that allows users to receive, directly into their PC's, the same digital video, audio, and related information signals received in conventional DTH systems. The receiver station in this PC-based system includes a local satellite receiver dish similar to that of a conventional IRD system, but the IRD functions are implemented within the PC architecture through the use of one or more circuit boards that are inserted into the PC. The decoded outputs from these boards are displayed on the PC's monitor, or may be output to a conventional video display (e.g., a television set) and/or other mass storage medium such as magnetic tape, digital video disk (DVD), optical or magnetic disk, video recorder (VCR), etc. Because the receiver station includes a personal computer, a large number of additional data and software-related services can also be downloaded directly to the PC, thereby offering a variety of services, including broadcast programming, pay-per-view events, audio programming, data services, webcasting, software downloads and other data or software-related services.
While known program guides have advantages, there is still room for improvement, particularly when considering the large number of data, software, video, audio, pay-per-view and other programming services available through present and future DTH satellite broadcast services. For example, the viewable display generated from electronic program guide data tends to be presented primarily as text laid out in a grid. The processing power of currently available IRD's, while appropriate for current DTH programming services, inherently limits how the program guide can be displayed, how much information can be incorporated into the guide, and how quickly and efficiently a user can move through the guide. These program guides are therefore essentially limited to conveying program availability and tuning information, and do not have the organization and flexibility to effectively support other services such as software downloads, webpage links and downloads, data services, and other functions.
Accordingly, for broadcast systems having a large number of services that deliver a large amount of data to relatively sophisticated receiver stations (e.g., a PC), there is a need for a broadcast electronic program guide and an associated viewable display format and content that significantly enhances how the program guide can be displayed, how much information can be incorporated into the guide, and how quickly and efficiently the user can move through the guide.